1. Field of the Invention
The present invention relates to a dielectric composition and an electronic component.
2. Description of the Related Art
Examples of an electronic component including a dielectric film include thin-film capacitors, thin-film filters for high frequency, and the like. These components are widely used as compact high-performance electronic components and are required to have higher capacitance, a small change in capacitance with a change in temperature, and excellent resistance to high voltage. In recent years, as highly functional devices such as smart phones and notebook personal computers have been further downsized and sophisticated, the electronic components have been strictly required to be more compact and smart.
In order to cope with such requirements, for example, thin-film capacitors including dielectric films with reduced thickness are under development. Reducing the thickness of films allows a capacitor to have increased capacitance and, however, causes a problem in that the resistance to high voltage drops and desired characteristics are not achieved.
In general, for example, amorphous SiOx films are used, as dielectric films in DRAM capacitors for semiconductor integrated circuits. However, in the case of using amorphous SiOx in a thin-film capacitor, dielectric films need to be thin in order to achieve higher capacitance because the relative permittivity of amorphous SiOx is low, 2 to 3. Therefore, a thin-film capacitor containing amorphous SiOxdoes not have good resistance to high voltage. Thus, in order to obtain a compact highly functional thin-film capacitor, a dielectric material having high relative permittivity and nigh dielectric strength needs to he used.
For materials with higher relative permittivity, for example, Science direct Physica B 348 (2004) 440-445, Preparation and characterization of sol-gel derived CaZrO3 dielectric thin film for high-k applications (Non Patent Document 1) discloses that a Ca—Zr—O amorphous film is formed by varying post-deposition heat-treatment temperature for a CaZrO3 thin-film. In this document, it is confirmed that the Ca—Zr—O amorphous film has a dielectric strength of about 3.0 MV/cm to 3.5 MV/cm and a relative permittivity of about 18.
Furthermore, Japanese Unexamined Patent Application Publication No. 2008-256555 (Patent Document 1) discloses that defects due to the strain of the interface between metal and dielectric are suppressed with an amorphous composite metal oxide thin-film obtained by forming an amorphous dielectric made of an oxide of Ba and/or Sr and Ti on copper foil provided with a metal thin-film containing one or more selected from the group consisting of Cr, Mi, Au, and Ag and insulating properties are thereby ensured. In this document, it can be confirmed that the relative permittivity on a level with a yield of more than 80% is 12.2 to 19.9 as determined by calculation.